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Hollenbj
Tinkerer
Username: Hollenbj

Post Number: 71
Registered: 03-2012

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Posted on Saturday, July 14, 2012 - 08:32 pm:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Moderator/Admin Only) Ban Poster IP (Moderator/Admin only)

I've asked this question before, but I think the subject line was misleading.

I'm repairing a Canon IIF that seems to not latch the first curtain when winding on. I've disassembled the camera somewhat but don't know exactly where the first curtain latch is located (I know where it is on Leica IIIc or IIIf). I know its not under the top plate (already went under there to see the speed mechanism and clean the rangefinder).

My guess is the latch is at the bottom of the large drum but that area is encased and I can't see in there very well. I would love to know if that's where I have to go before disassembling the bottom of the shutter carriage. It looks like I will really be getting deep if I do that (for instance, I will need to re-tension the curtains afterward).

Any help, shared experiences, important tips, unimportant tips will be very much appreciated. I usually dig right into my repairs, but I like this camera so much, I'm more cautious about hacking away.

Thanks!
jeff.
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John_shriver
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Username: John_shriver

Post Number: 91
Registered: 12-2006

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Posted on Friday, July 27, 2012 - 09:16 pm:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Moderator/Admin Only) Ban Poster IP (Moderator/Admin only)

There's a post sticking down out of the bottom of the sprocket wheel. It catches a post sticking up from the top of the gear under the sprocket wheel. That gear moves down as you press the shutter button, which lets the opening curtain shaft start turning (through the gears).

If that gear train on the bottom of the camera isn't properly timed, that pair of posts won't do their work. You're on the wrong tooth of the gear somewhere.

So the wind knob turns the sprocket wheel through gears under the top plate of the camera. That causes the post at the bottom of the sprocket wheel to catch the post on the gear. The gear turns the shutter drum to the cocked position.
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Hollenbj
Tinkerer
Username: Hollenbj

Post Number: 73
Registered: 03-2012

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Votes: 0 (Vote!)

Posted on Monday, July 30, 2012 - 01:07 pm:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Moderator/Admin Only) Ban Poster IP (Moderator/Admin only)

John,

Thanks. I can see the play between the posts and figured I was mis-registered somehow. I really don't know how I managed to get there, I just replaced the wind shaft which I wouldn't think would cause mis-timing.

I'm dreading the attempt at accessing those gears. The design of the bottom portion of the shutter carriage means more disassembly than I'm used to. I'll first remove the slow speed unit and see if I can get enough access from that side, else I need to consider sending this repair to someone with more guts than I.

Thanks very much for your help.
jeff.

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